#
# Copyright (c) 2011, EPFL (Ecole Politechnique Federale de Lausanne)
# All rights reserved.
#
# Created by Marco Canini, Daniele Venzano, Dejan Kostic, Jennifer Rexford
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
#   -  Redistributions of source code must retain the above copyright notice,
#      this list of conditions and the following disclaimer.
#   -  Redistributions in binary form must reproduce the above copyright notice,
#      this list of conditions and the following disclaimer in the documentation
#      and/or other materials provided with the distribution.
#   -  Neither the names of the contributors, nor their associated universities or
#      organizations may be used to endorse or promote products derived from this
#      software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
# SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#

import random

import logging
log = logging.getLogger("nice.mc.strat.rwalk")

class RandomWalk:
	def __init__(self, model_checker):
		self.model_checker = model_checker
		self.myrandom = random.Random()
		self.seed = None

	def setSeed(self, seed):
		self.seed = seed
		print seed
		self.myrandom.seed(self.seed)

	def getEnabledActions(self):
		actions = self.model_checker.model.getAllEnabledActions()
		if len(actions) > 0:
			return [self.myrandom.choice(actions)]
		else:
			return actions

	def onEnableAction(self, node, action):
		return action
	
	def chooseAction(self, enabled_actions):
		return enabled_actions.pop(0)

	def visitModel(self, model):
		pass
